Electrical instrument



May 13, 1930. K. KLEIN ELECTRICAL lINSTRUMENT Filed July 25, 192B ggg www F l Il Patented May 13, .1930' KARLILEIN, or sr.- LoUIs, MISSOURI j nLnc'rInear,v INSTRUMENT Appncafion mea July 23, 192s. serial.- Nd. 294,829. i

This invention relates to improvementsin electrical instruments, and consists in lthe novel construction hereinafter disclosed. j

This application is a'continuation in part of my copendingV application Serial No. 174,901, filed March 12, 1927, lfor combined voltmeter and ammeter.

An obj ect of the invention is to provide an electrical instrument designed to be connected into an electriccircuit to indicate the voltage and amperage on concentric dials supported by a common case. j

Another object` of the invention is to provide a combined voltmeter andV ammeter in which the dials are arranged onconcentric axes, and the indicators or pointers'of which are concentrically mounted', in combination with means for actuating thepointersto indicate the voltage and amperage of thecur rent passing over the circuit into which the instrument is connected.

' Additional advantages of the construction will be appa-rent from the following detailed description thereof taken in connection with the accompanying drawing,in which j F ig. 1 is a front elevation of the instrument.

Fig. 2 is a vertical section through the instrument. Y

Fig.

Fg. l4 is a diagrammatic viewillustrating`r the electrical connections and the operative parts of the instrument. n j

In the embodiment of the invention illustrated in the drawing, thev device is shown as including a case comprising a cylindrical Ine-y tallic Wall 1 joined at oneendby a back Wall 2', e

panel 10 of glass or other transparent material, said panel l0 being held in adjustment by Fig. 3 is a vertical section at right angles to a rimll thatlthreadsl into the wal-l 1. A spacl ing ring 12 is disposed between the panel 1G; and the wall 6, andthe joint between the panel 10 and the rim ll'may be sealed yby a aslet 13, if desired,`to prevent dustv or dirt from entering the instrument case. V n j Upon the outer face of the Wall 6 are twoconcentric arcuate dials 14 and 15, theup'perV one of which is graduated for voltage indica-- tions,and the lowerone of which is' graduated for amperage indications.

-Vithin the chamber 7 is a .coil 16 of low;

resistance material,lsaid coil being connected at one endv to a binding postv 17 that` is insu-'f latedby an insulating bushing 18V4 fro'mthe case.' A lead 19 extends from the binding post 17 l to the coil. The binding post 17 is arranged forA exterior connection with one lead 20 of an electric' circuit. 'The opposite end of thev coil1`6is connected with a binding post21 which post 21 has electrical contactv with the metallicwall 1. The binding post is arranged for connection with `an extensionV 22 of the leady20, thecoirl 16 therefor being in series- WithV the source of` power for energizing the. lead 20. v 'Arranged Within and cooperating with-:the coil' 16 isan armature 23v which is raised and lowered'by the current traversing the coil 16'v coordinate with the current voltage, it being understood that the action of the armature in the coil is the usual yaction of a solenoid.,

The armature 23 hasy connected with its lower enda rack bar 24 of nonmagmeti'c` material. The armature is normally actuated down.- wardly by ka contractile spring 25y connected at one end to a pin 26 carried by the bar and at'the other end to a. permanent stationary part of the case. As illustrated, the lower endof the spring is connected to a guide plate `27 for the bar 24. Above the partition 9it1s also preferable to provide a second` guide plate 28, so as to preserve the bar in vertical alinement. The bar v24 has its.y lower end formedto providek a rack 2.9, which meshes with a pinion Ocarried on aj sleeve 3,1;

The sleeve 31y extends through an opening Y 82 in the wall 6,which opening constitutes :a

bearing for saidv sleeve. The sleeve is` provided with a flange 33. that seats, against the; rear forwardly of the wall 6 into the space between said wall and the panel 10. The forward end of the sleeve carries a pointer or 'indicator 34 which coordinates with the dial 15, it being understood that the sleeve 31ris rockedthrough the rack and` pinion connecin relation to the dial 15.

tion when the armature 23 is 'raised by the influence of the current traversing the coil" 16. Since the extent of movement of the armature, and therefore the bar 24, is coordinate with the amperage of the 'current traversing the coil 16adirect reading of the amperage will be translated and indicated through the connections just described, .so

that an accurate indication ofthe amperage is providedfby the position of the'pointer 34 AInthe. lower part of Vthe L case is located the mechanism for indicating voltage. 'Ihis mechanism comprises a coil of high resistance material, Vwhich coil Vis electrically connected with the case1 by a bar 36, the current therefor flowing from the binding post .21, which is electrically connected withthe lead 20, enters thecoil 35thr1ough the bar 36. The opposite end of the coil 35 is connected with abinding post 37 which Vis `insulated from theY case by an insulating bushing 38, said binding post beingy arranged for exterior connection with the-opposite line 39 of the main circuit. The coil 35 therefore is connectedy in parallel with the main circuit i leads. A-permanent magnet 40 is supported bythe wall 5 ,in such-position Athat the ends' Athereof lie within the 'field of the' coil 35.

Located within theL terminals of the magnetY 40is an armature 41, preferably of soft' iron,

' said armature being vdirectly carriedby aspindle 42 which-extends rearwardly andforwardly from therarmature. The rearend of the spindle is ournaled in a thimble bearing 43 in the wall 5, andthe forward' end ofsaid Y spindle extends through theV sleeve A31to a point forward ofthe front extremity thereof. The spindle-42 carries at its forward extremity a pointer or-indicator 44, which is of slightly 'greater length than the indicator 34, said pointer 44 lccp-ordinating with the dial 14 for voltage indications. The spindle 42 is normally held at the point of restby a Vcoil spring 45 connected aton'e-end toa stationary part of the case (as illustrated', to the wall 5) and at the other tothe spindle 42.

" The armature 41 is held in balance at the point of rest by the magnetic force of the permanent magnet 40 operating 'in' lopposition to the spring 45. When the current traverses the coil 35, afield of force issetV u which reacts with the field of force produced by the .permanentmagnet 40, thereby tending Vto .rotate the armature in coordination with thevoltage of the current traversing the coil 35. The extent of movement of the armature is calibrated with the volt indicating dial and, therefore, a direct positive reading of the voltage is accomplished by the extent of movement of the indicator 44 on the dial 14. v From the foregoingit will be seen that I have combined in a single instrument a voltmeter andan ammeter, the registrations ofl both of which-are readily observable at the same time, so that the desired information aorded by use of these vtwo instruments may be quickly obtained. The construction and relationship of the parts may be varied within equivalent limits without ldeparture from the nature and principle of the invention. .y What I claim and desire to secure by LettersPatent is 2-VV l Y v 1. An electric instrument ofthe class described comprising a caseseparated into nonconducting compartments, dialsV carried in. the case and visible through one wall thereof, a pair ofindicators cooperating respectively with said dials, said indicators being co-axially alined, an electric actuator responsive to amperage located in one of said comparti` ments-for operating one of said indicators, and an electric actuator responsive to voltageV located inthe other 'of said' compartments for actuating the other of said indicators. y' 2. An electric instrument of the classde- Vscribed comprising a case, dials carried in the caseand visible through one wall thereof, a pair of indicators cooperating respectively with said dials, said indicators being coaxialf ly alined, a bar supported in and slidable within the case, a rack and pinion connection between the bark and one of said indicators, an armature carried bysaid bar, a coil energizedby a main electric circuit and cooperscribed comprising a' case, a pair of indicator 3. An electric instrument of the class `deshafts coaxially alined and supported in the 1 case,'a pair of cooperating VYconcentric dials coordinating respectively vwith said indicators, a slidable bar mounted in the case, a spring normally actuating the bar to one position, an electric means for moving said bar connected in series with a circuit, said means being responsive to 'amperage' of the circuit, connections between the bar and one indicator shaft for moving the indicator responsive to amperage, and a second electric means connected with a circuit responsive to voltage, said means, being adapted to rotate the other indicator shaft to indicate voltage.

a v Y Y l f KARL KLEIN.

izo 

